HEMCO upper plenum with 62mm TB for 1986/1987 Buick Grand National/WE-2 T-Type 3.8L turbocharged engine. $175 shipped
This upper plenum has a radical new design with the goal to improve the air flow distribution to all cylinders, thus evening out the power generated from the engine. This is accomplished by changing the air flow path into the manifold by means of a physical design change. The new design incorporates a 90 degree turn with a narrow opening into the intake manifold. This design makes the intake manifold think a throttle body is sitting directly on top of it.
This upper plenum has a radical new design with the goal to improve the air flow distribution to all cylinders, thus evening out the power generated from the engine. This is accomplished by changing the air flow path into the manifold by means of a physical design change. The new design incorporates a 90 degree turn with a narrow opening into the intake manifold. This design makes the intake manifold think a throttle body is sitting directly on top of it.
